Sound-modifying means



E. CASSCA. SOUND MODIFYING MEANS.

APPLICATION man rss.s.19|9.

1,342,662. mmm@ 8, 1920.

UNITED STATES PATENT o FFicE,

ERWIN CASSCA, 0F GLOVERSVILLE, NEW YORK.

SOUND-MODIFYING MEANS.

Specification of Letters Patent.

Patented June 8, 1920.

Application'led February 3, 1919. Serial No. 274,774.

boxes for phonographs or the like, and `particularly to sound modifying means for receivingj the diaphragml vibrations .at the point of maximum amplitude, the minor v1- bration being absorbed or deadened, to thereby avoid the interference which would otherwise impair the pure reproduction. p

The invention in the preferred form 1s illustrated in. the accompanying drawings, in which:

Figure 1, is a section in elevation showing K my improved sound modifier. Fig. 2, is a cross section taken on line 2-2 of Fig. l. A complete description of the sound box herein shown Will be found in my. copending application for improvements 1n sound boxes .for phonographs, or the like, filed June 11, 1917 Serial #173925, therefore I shall here limit myself to the description of the particular sound modifying means forming the subject matter of this application.

To avoid variations in the vibrations of the diaphragm in the reproduction, I provide what I term a sound modifier, in the use of which the vibrations of the diaphragm beyond the point of maximum amplitude thereof are deected or dampened, with the eilect to render the sound waves delivered to the horn more sharp and clear.

'To provide for this sound modifier the upper portion of the wall of the sound opening is recessed at 10 to receive a sleeve extension 11, the upper edge or' which is vertically slotted at diametrically opposite points, as at 12. The sound modifier comprises a series of connected sections 13, of substantially similar structure but varying in diameter. Each section comprises an annular wall 14 having its minimum diameter at a point approximately half the height thereof, the wall flaring above and below said minimum line. The upper edge of the annular wall forming the section is projected downwardly, and formed in a return band, terminating in spaced relation to the wall,` and forming with said wall, an ap. 5,5:` proximately closed annular chamber 15 open' ing only from beneath. As previously stated, the respective sections, of which four are here shown, are of successively increased diameter from the lower to the upper portion of the modifier, and each of the said sections above the lower sections have, at diametrically opposite points, depending l strips; 16' by means of which the particular sectiohf is secured to the next lowermost section. There is thus provided an annular series of slot like openings 17 between the -1' lower edge of each section andthe rounded wall of the next lowermost section, providl i ing for the sound entrance into the modifier at a series of distinct but uniformly ar- .y ranged points. The uppermost section is?. provided with projecting pins or strips 184'; adapted to seat in the slots 12 of the sleeve 11, whereby the modifier is removably sup-.75 ported within the sleeve in a position dii rectly and centrally above the diaphragm.

The sound box is provided with the usual casing 19 secured to the base with the sleeve, the casing rising above the sleeve and having an extension 20 to which the hornor other Sound conveyei 21 may be removably secured. 'i

I claim A sound box having a diaphragm and a tone modifier removably carried by. said box above the diaphragm, said modifierl comprising a series of superposed sections of increasing diameter from the diaphragm, each section being connected to the one below at 90 determinate points to provide slotted openings-between the sections, each section liaving an annular peripheral ,-chaiiilier-said chamber being open from beneath.

In witness Whereor` I have hereunto subscribed my name this 3d day of June. i918. V

ERlVIN CASSCA. 

